Automotive transmissions require adequate hydraulic pressure for reliable operation. Currently, solenoid valves are the most common way for regulating hydraulic pressure in transmissions, such as in a clutch control valve, and the pressure is measured using a pressure transducer or some other external pressure sensor attached to the solenoid valve. In a clutch control valve, for example, the hydraulic pressure indicates the force at which the clutch is engaging. The additional sensing circuitry, however, adds complexity to the automotive transmission control system. Further, adding sensors and connecting circuitry to the solenoid valves require extra parts and extra wiring, increasing the cost and complexity of the automotive transmission system.
Therefore, there is a need for a device that measures the hydraulic pressure of a solenoid valve while minimizing the extra circuitry needed to conduct the pressure measurement.